This may seem backwards but here goes.... The dead section would have to be long enough to hold the complete pass train. To prevent the power from flowing through the pass car, a relay (controlled from an outside insulated rails prior to the dead section. would keep the dead section "hot" until the train leaves the outside rail insulated section. The insulated section would only come into play when the bridge is open. How would you wire it??? not really sure. This may be the same as Don's post above.
Greg, the isolated bridge approaches and the bridge track are separately powered using a lock-on (or alternate method). The controls inside the lift bridge and bascule bridge shuts off power in the isolated track section with the lock-on (and the bridge track and other approach track due to loss of contact by the bridge track to the approach track with the lock-on) when the bridge is lifted, and restores power when the bridge is fully lowered.
